LXR qemu/block/parallels.c

   1/*
   2 * Block driver for Parallels disk image format
   3 *
   4 * Copyright (c) 2007 Alex Beregszaszi
   5 *
   6 * This code is based on comparing different disk images created by Parallels.
   7 *
   8 * Permission is hereby granted, free of charge, to any person obtaining a copy
   9 * of this software and associated documentation files (the "Software"), to deal
  10 * in the Software without restriction, including without limitation the rights
  11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12 * copies of the Software, and to permit persons to whom the Software is
  13 * furnished to do so, subject to the following conditions:
  14 *
  15 * The above copyright notice and this permission notice shall be included in
  16 * all copies or substantial portions of the Software.
  17 *
  18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  24 * THE SOFTWARE.
  25 */
  26#include "qemu-common.h"
  27#include "block_int.h"
  28#include "module.h"
  29
  30/**************************************************************/
  31
  32#define HEADER_MAGIC "WithoutFreeSpace"
  33#define HEADER_VERSION 2
  34#define HEADER_SIZE 64
  35
  36// always little-endian
  37struct parallels_header {
  38    char magic[16]; // "WithoutFreeSpace"
  39    uint32_t version;
  40    uint32_t heads;
  41    uint32_t cylinders;
  42    uint32_t tracks;
  43    uint32_t catalog_entries;
  44    uint32_t nb_sectors;
  45    char padding[24];
  46} __attribute__((packed));
  47
  48typedef struct BDRVParallelsState {
  49    int fd;
  50
  51    uint32_t *catalog_bitmap;
  52    int catalog_size;
  53
  54    int tracks;
  55} BDRVParallelsState;
  56
  57static int parallels_probe(const uint8_t *buf, int buf_size, const char *filename)
  58{
  59    const struct parallels_header *ph = (const void *)buf;
  60
  61    if (buf_size < HEADER_SIZE)
  62        return 0;
  63
  64    if (!memcmp(ph->magic, HEADER_MAGIC, 16) &&
  65        (le32_to_cpu(ph->version) == HEADER_VERSION))
  66        return 100;
  67
  68    return 0;
  69}
  70
  71static int parallels_open(BlockDriverState *bs, const char *filename, int flags)
  72{
  73    BDRVParallelsState *s = bs->opaque;
  74    int fd, i;
  75    struct parallels_header ph;
  76
  77    fd = open(filename, O_RDWR | O_BINARY | O_LARGEFILE);
  78    if (fd < 0) {
  79        fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
  80        if (fd < 0)
  81            return -1;
  82    }
  83
  84    bs->read_only = 1; // no write support yet
  85
  86    s->fd = fd;
  87
  88    if (read(fd, &ph, sizeof(ph)) != sizeof(ph))
  89        goto fail;
  90
  91    if (memcmp(ph.magic, HEADER_MAGIC, 16) ||
  92        (le32_to_cpu(ph.version) != HEADER_VERSION)) {
  93        goto fail;
  94    }
  95
  96    bs->total_sectors = le32_to_cpu(ph.nb_sectors);
  97
  98    if (lseek(s->fd, 64, SEEK_SET) != 64)
  99        goto fail;
 100
 101    s->tracks = le32_to_cpu(ph.tracks);
 102
 103    s->catalog_size = le32_to_cpu(ph.catalog_entries);
 104    s->catalog_bitmap = qemu_malloc(s->catalog_size * 4);
 105    if (read(s->fd, s->catalog_bitmap, s->catalog_size * 4) !=
 106        s->catalog_size * 4)
 107        goto fail;
 108    for (i = 0; i < s->catalog_size; i++)
 109        le32_to_cpus(&s->catalog_bitmap[i]);
 110
 111    return 0;
 112fail:
 113    if (s->catalog_bitmap)
 114        qemu_free(s->catalog_bitmap);
 115    close(fd);
 116    return -1;
 117}
 118
 119static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)
 120{
 121    BDRVParallelsState *s = bs->opaque;
 122    uint32_t index, offset;
 123    uint64_t position;
 124
 125    index = sector_num / s->tracks;
 126    offset = sector_num % s->tracks;
 127
 128    // not allocated
 129    if ((index > s->catalog_size) || (s->catalog_bitmap[index] == 0))
 130        return -1;
 131
 132    position = (uint64_t)(s->catalog_bitmap[index] + offset) * 512;
 133
 134//    fprintf(stderr, "sector: %llx index=%x offset=%x pointer=%x position=%x\n",
 135//      sector_num, index, offset, s->catalog_bitmap[index], position);
 136
 137    if (lseek(s->fd, position, SEEK_SET) != position)
 138        return -1;
 139
 140    return 0;
 141}
 142
 143static int parallels_read(BlockDriverState *bs, int64_t sector_num,
 144                    uint8_t *buf, int nb_sectors)
 145{
 146    BDRVParallelsState *s = bs->opaque;
 147
 148    while (nb_sectors > 0) {
 149        if (!seek_to_sector(bs, sector_num)) {
 150            if (read(s->fd, buf, 512) != 512)
 151                return -1;
 152        } else
 153            memset(buf, 0, 512);
 154        nb_sectors--;
 155        sector_num++;
 156        buf += 512;
 157    }
 158    return 0;
 159}
 160
 161static void parallels_close(BlockDriverState *bs)
 162{
 163    BDRVParallelsState *s = bs->opaque;
 164    qemu_free(s->catalog_bitmap);
 165    close(s->fd);
 166}
 167
 168static BlockDriver bdrv_parallels = {
 169    .format_name        = "parallels",
 170    .instance_size      = sizeof(BDRVParallelsState),
 171    .bdrv_probe         = parallels_probe,
 172    .bdrv_open          = parallels_open,
 173    .bdrv_read          = parallels_read,
 174    .bdrv_close         = parallels_close,
 175};
 176
 177static void bdrv_parallels_init(void)
 178{
 179    bdrv_register(&bdrv_parallels);
 180}
 181
 182block_init(bdrv_parallels_init);
 183